英文阅读：巧克力能提高记忆力和心脏健康

From VOA Learning English, this is the Health Report. Can eating a chocolate bar every day really prevent age-related memory loss? No. Can eating chocolate cake for breakfast, lunch and dinner be good for your heart? Again, the answer is no. That would be too good to be true. But new research shows that large amounts of flavanols, substances found in cocoa, tea and some vegetables, may reverse age-related memory failure. Another study is looking to see if high levels of cocoa flavanols can help prevent heart attacks and strokes. Flavanols found in dark chocolate are known to increase blood flow in the part of the brain that controls memory. They also help prevent heart disease by lowering blood pressure and "bad" cholesterol. A new study published online in Nature Neuroscience found that cocoa flavanols reverse minor memory loss in older adults. A company that makes chocolate helped to pay for the study. Brain processes decrease as we age. By the time we reach our 50s and 60s we may have trouble remembering simple things such as the names of new people we meet or where we put our car keys. Dr. Scott Small is a professor of neurology at Columbia University in New York City. He is the lead writer of a research paper describing the effects of cocoa flavanols on brain activity. The study involved 37 volunteers aged between 50 and 69. Researchers gave them a high-level flavanol drink made from cocoa beans or a low-level flavanol drink. For a period of three months, some subjects got 900 milligrams of flavanol a day. The others got 10 milligrams of flavanol each day. Brain imaging and memory tests were given to each study subject before and after the study. Dr. Small says that the subjects who had the high-level flavanol drink showed much improvement on memory tests. The researchers warn that more work is needed because this study was performed on a small group. Researchers at Brigham and Women's Hospital in Boston, Massachusetts recently announced plans to do just that. Dr. JoAnn Manson is the lead researcher of a four-year study involving 18,000 adults. This study will use flavanol capsules. "This capsule of cocoa flavanols will avoid having the calories and the sugar and the saturated fat found in chocolate." The study subjects will be divided into two groups and will take two pills a day. The capsules will all look the same. But, one group's capsules will contain flavanols. The other group will take capsules made of an inactive substance, or placebo. Dr. Manson says that a person would have to eat ten times a normal amount to get the flavanols in just one flavanol pill. "The amount of chocolate that it would take in order to have this amount of cocoa flavanols would be more than ten times the amount that people would ordinarily eat." But Dr. Small says people should not necessarily start eating more chocolate. He says a person would have to eat a huge amount of chocolate to get the level of flavanol given to the test subjects. He also says many manufacturers remove the flavanols from their chocolate products. Dr. Small says a cocoa-based flavanol extract may be developed in the future. He says that more studies are needed to see how much flavanol is good for human health. I'm Anna Matteo. 更多英语学习:企业英语